About John

I was educated as a coding, communication, and information theorist at MIT but became a theoretical computer scientist in order to understand why decoders for error correcting codes were so much more bigger than encoders. The result was a series of papers and a book (Complexity of Computing, 1976) that demonstrated that the size and depth of a circuit are key measures of the computational complexity of the function that is computed by the circuit. Circuit complexity is now a principal topic in theoretical computer science.

After completing my PhD at MIT, I worked for Bell Laboratories in New Jersey. Within three years I was off to Brown as an engineering faculty member. In the early 1970s it became apparent to Andy van Dam and Peter Wegner, who were in Applied Math, and me that we should pool our resources and form the Program in Computer Science. By the late 1970s we saw that we needed to have departmental status if we were going to obtain the resources needed to ensure that Brown could take advantage of this new, exploding research area called "computer science." Starting a new department was a challenge to all of us. Some of us had to serve as chair. Andy was our first chair and I was the second, serving from 1985 to 1991. Recruiting a high quality faculty was our first priority, which we did very successfully and continue to do today.
Outside of Computer Science but within Brown I have served on many faculty committees and as chair of many key committees. At the professional level I have served on several editorial boards and committees as well as a member of the visiting committee for the MIT Department of Electrical Engineering and Computer Science, my undergraduate and graduate department, which was a great deal of fun.
On the personal side, my wife and I have four children all of whom graduated from Brown and are leading interesting and happy lives. We have traveled with them on sabbatical
leaves to the Netherlands, France, and England.

What do you focus on in your research? Any recent advances?

I am now very actively involved in cybersecurity from both a policy and technology point of view. This is an interest that I developed as a result of spending the 2009-2010 academic year in the U.S. Department of State as a Jefferson Science Fellow. Over the last decade I have done research and published on computational nanotechnology, the I/O efficiency of multicore chips, and coded computation. The latter involves adding redundancy to data so that if errors occur during a computation, they can be corrected.

What do you like teaching classes about?

I like to teach computer sciencecourses that involve models of computation and related analysis. I'm a big believer in developing good models from which one can derive important limitations on computation through analysis. My last book, Models of Computation, published in 1998, deals with this topic.

I also like to teach courses that involve both policy and technology in cybersecurity. This is an area whose importance has risen rapidly recently due to the globalization of the Internet and the fact that our software, hardware and networks were not designed with security in mind.

How did you become interested in computer science?

As explained above, I became a computer scientist (by accident) in order to understand why decoders for error correcting codes, as seen in practice, were so much more complex than the encoders that added redundancy to messages.

What is your favorite thing about Brown?

I very much like the atmosphere at Brown. Faculty, students and staff are generally happy being here. They are all nice, pleasant and intelligent people. It's fun to be around them.

Any hobbies or passions?

I enjoy exploring ideas. Cybersecurity is my current focus. I also read extensively in science and have many friends who are scientists with whom I exchange ideas. At one time, I did the same with friends in economics.